Synthesis and photophysical properties of octa-substituted phthalocyaninato oxotitanium (IV) derivatives
- Tau, Prudence, Nyokong, Tebello
- Authors: Tau, Prudence , Nyokong, Tebello
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/283881 , vital:55999 , xlink:href="https://doi.org/10.1142/S1088424606000399"
- Description: The synthesis, spectral and photophysical properties including fluorescence quenching of the following octa-substituted oxotitanium phthalocyanines are reported: 2,3,9,10,16,17,23,24-octaphenoxyphthalocyaninato titanium(IV) oxide, 2,3,9,10,16,17,23,24-[octakis(4-t-butylphenoxyphthalocyaninato)]titanium(IV) oxide, 2,3,9,10,16,17,23,24-{octakis[(4-benzyloxy)phenoxy]phthalocyaninato}titanium(IV) oxide and 2,3,9,10,16,17,23,24-octaphenylthiophthalocyaninato titanium(IV) oxide. The complexes are characterized by 1H NMR, IR and UV-vis spectroscopies. Their photophysical properties are presented where moderate fluorescence quantum yields (0.14-0.19) and lifetimes were determined. Varied triplet quantum yields were obtained and the triplet lifetimes (40-100 μs) were short.
- Full Text:
- Authors: Tau, Prudence , Nyokong, Tebello
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/283881 , vital:55999 , xlink:href="https://doi.org/10.1142/S1088424606000399"
- Description: The synthesis, spectral and photophysical properties including fluorescence quenching of the following octa-substituted oxotitanium phthalocyanines are reported: 2,3,9,10,16,17,23,24-octaphenoxyphthalocyaninato titanium(IV) oxide, 2,3,9,10,16,17,23,24-[octakis(4-t-butylphenoxyphthalocyaninato)]titanium(IV) oxide, 2,3,9,10,16,17,23,24-{octakis[(4-benzyloxy)phenoxy]phthalocyaninato}titanium(IV) oxide and 2,3,9,10,16,17,23,24-octaphenylthiophthalocyaninato titanium(IV) oxide. The complexes are characterized by 1H NMR, IR and UV-vis spectroscopies. Their photophysical properties are presented where moderate fluorescence quantum yields (0.14-0.19) and lifetimes were determined. Varied triplet quantum yields were obtained and the triplet lifetimes (40-100 μs) were short.
- Full Text:
Teacher education for Mathematical Literacy: a modelling approach
- Brown, Bruce J L, Schäfer, Marc
- Authors: Brown, Bruce J L , Schäfer, Marc
- Date: 2006
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/141040 , vital:37939 , DOI: 10.4102/pythagoras.v0i64.98
- Description: This paper reports on a study of the extent to which question design affects the solution strategies adopted by children when solving linear number pattern generalisation tasks presented in pictorial and numeric contexts. The research tool comprised a series of 22 pencil-and-paper exercises based on linear generalisation tasks set in both numeric and two-dimensional pictorial contexts. The responses to these linear generalisation questions were classified by means of stage descriptors as well as stage modifiers. The method or strategy adopted was analysed and classified into one of seven categories. In addition, a meta-analysis focused on the formula derived for the nth term in conjunction with its justification. The results of this study strongly support the notion that question design can play a critical role in influencing learners' choice of strategy and level of attainment when solving pattern generalisation tasks. An understanding of the importance of appropriate question design has direct pedagogical application within the context of the mathematics classroom.
- Full Text:
- Authors: Brown, Bruce J L , Schäfer, Marc
- Date: 2006
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/141040 , vital:37939 , DOI: 10.4102/pythagoras.v0i64.98
- Description: This paper reports on a study of the extent to which question design affects the solution strategies adopted by children when solving linear number pattern generalisation tasks presented in pictorial and numeric contexts. The research tool comprised a series of 22 pencil-and-paper exercises based on linear generalisation tasks set in both numeric and two-dimensional pictorial contexts. The responses to these linear generalisation questions were classified by means of stage descriptors as well as stage modifiers. The method or strategy adopted was analysed and classified into one of seven categories. In addition, a meta-analysis focused on the formula derived for the nth term in conjunction with its justification. The results of this study strongly support the notion that question design can play a critical role in influencing learners' choice of strategy and level of attainment when solving pattern generalisation tasks. An understanding of the importance of appropriate question design has direct pedagogical application within the context of the mathematics classroom.
- Full Text:
Teacher-community cooperation to promote sustainability of wetlands in Kenya
- Authors: Ndaruga, Ayub M , Irwin, Pat
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/373860 , vital:66728 , xlink:href="https://www.ajol.info/index.php/sajee/article/view/122727"
- Description: This study was undertaken with 83 teachers from 54 primary schools in Kenya. Its purpose was to establish how teachers relate with the local community and how they harness this interaction to promote sustainability of wetlands within their locality. Data were collected using questionnaires, interviews and observation. Results of the study indicated that teachers acknowledge the value of, and threats to, their local wetlands. Some teachers reported interacting and engaging in diverse activities with members of the community to conserve the local wetlands. Forums for interaction and action mentioned by the teachers included public baraza, women’s groups, church, youth groups, local community, parents’ meetings and environmental days. Use of these forums differed. The approaches used to involve the community in awareness and action ranged from theoretical arguments to visits to wetlands, use of wetland resources, ecomanagement and political action. The responses by teachers revealed lack of engagement with the real local wetland problems. This study demonstrated existence of a potential but under-utilised opportunity that can be harnessed by environmental education programmes to champion the sustainability of wetlands.
- Full Text:
- Authors: Ndaruga, Ayub M , Irwin, Pat
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/373860 , vital:66728 , xlink:href="https://www.ajol.info/index.php/sajee/article/view/122727"
- Description: This study was undertaken with 83 teachers from 54 primary schools in Kenya. Its purpose was to establish how teachers relate with the local community and how they harness this interaction to promote sustainability of wetlands within their locality. Data were collected using questionnaires, interviews and observation. Results of the study indicated that teachers acknowledge the value of, and threats to, their local wetlands. Some teachers reported interacting and engaging in diverse activities with members of the community to conserve the local wetlands. Forums for interaction and action mentioned by the teachers included public baraza, women’s groups, church, youth groups, local community, parents’ meetings and environmental days. Use of these forums differed. The approaches used to involve the community in awareness and action ranged from theoretical arguments to visits to wetlands, use of wetland resources, ecomanagement and political action. The responses by teachers revealed lack of engagement with the real local wetland problems. This study demonstrated existence of a potential but under-utilised opportunity that can be harnessed by environmental education programmes to champion the sustainability of wetlands.
- Full Text:
The Condictio Indebiti and Unjust Factors (1)
- Authors: Glover, Graham B
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/186869 , vital:44541 , xlink:href="file:///C:/Users/User/Downloads/69THRHR419%20(2).pdf"
- Description: Since the Supreme Court of Appeal has continued to avoid taking the step of recognising a general enrichment action,' the traditional enrichment actions of the common law remain fundamentally important to the operation of the law of unjustified enrichment in South Africa. Most significant of these is the condictio indebiti, which is probably the most well-known and liberally utilised enrichment action in South African law.2 In this article, the nature and scope of this condictio will be examined, and it will be shown that it has grown beyond its notionally traditional role of reversing payments or transfers made unjustifiably by mistake, to include causes of action in duress and protest. The implications of this for the condictio, as well as for the foundations of our enrichment law will then be examined, with reference to the two leading schools of enrichment law: the civilian school, typified by German law, and the common-law school, typified by English law.
- Full Text:
- Authors: Glover, Graham B
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/186869 , vital:44541 , xlink:href="file:///C:/Users/User/Downloads/69THRHR419%20(2).pdf"
- Description: Since the Supreme Court of Appeal has continued to avoid taking the step of recognising a general enrichment action,' the traditional enrichment actions of the common law remain fundamentally important to the operation of the law of unjustified enrichment in South Africa. Most significant of these is the condictio indebiti, which is probably the most well-known and liberally utilised enrichment action in South African law.2 In this article, the nature and scope of this condictio will be examined, and it will be shown that it has grown beyond its notionally traditional role of reversing payments or transfers made unjustifiably by mistake, to include causes of action in duress and protest. The implications of this for the condictio, as well as for the foundations of our enrichment law will then be examined, with reference to the two leading schools of enrichment law: the civilian school, typified by German law, and the common-law school, typified by English law.
- Full Text:
The Condictio Indebiti and Unjust Factors (2)
- Authors: Glover, Graham B
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/186880 , vital:44544 , xlink:href="///C:/Users/User/Downloads/69THRHR561%20(1).pdf"
- Description: Since the Supreme Court of Appeal has continued to avoid taking the step of recognising a general enrichment action,' the traditional enrichment actions of the common law remain fundamentally important to the operation of the law of unjustified enrichment in South Africa. Most significant of these is the condictio indebiti, which is probably the most well-known and liberally utilised enrichment action in South African law.2 In this article, the nature and scope of this condictio will be examined, and it will be shown that it has grown beyond its notionally traditional role of reversing payments or transfers made unjustifiably by mistake, to include causes of action in duress and protest. The implications of this for the condictio, as well as for the foundations of our enrichment law will then be examined, with reference to the two leading schools of enrichment law: the civilian school, typified by German law, and the common-law school, typified by English law.
- Full Text:
- Authors: Glover, Graham B
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/186880 , vital:44544 , xlink:href="///C:/Users/User/Downloads/69THRHR561%20(1).pdf"
- Description: Since the Supreme Court of Appeal has continued to avoid taking the step of recognising a general enrichment action,' the traditional enrichment actions of the common law remain fundamentally important to the operation of the law of unjustified enrichment in South Africa. Most significant of these is the condictio indebiti, which is probably the most well-known and liberally utilised enrichment action in South African law.2 In this article, the nature and scope of this condictio will be examined, and it will be shown that it has grown beyond its notionally traditional role of reversing payments or transfers made unjustifiably by mistake, to include causes of action in duress and protest. The implications of this for the condictio, as well as for the foundations of our enrichment law will then be examined, with reference to the two leading schools of enrichment law: the civilian school, typified by German law, and the common-law school, typified by English law.
- Full Text:
The effect of Ge, Si and Sn phthalocyanine photosensitizers on cell proliferation and viability of human oesophageal carcinoma cells
- Seotsanyana-Mokhosi, Itumeleng, Kresfelder, Tina, Abrahamse, Heidi, Nyokong, Tebello
- Authors: Seotsanyana-Mokhosi, Itumeleng , Kresfelder, Tina , Abrahamse, Heidi , Nyokong, Tebello
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/286115 , vital:56241 , xlink:href="https://doi.org/10.1016/j.jphotobiol.2005.12.004"
- Description: The photodynamic activity of water soluble mixed sulfonated metallophthalocyanines complexes: GePcSmix, SnPcSmix and SiPcSmix on human oesophageal carcinoma (SNO) cells are reported, and compared with the activity of the unmetallated H2PcSmix and of the newly synthesized water soluble adjacently substituted binaphthalo phthalocyanine (complex 3). The alkaline phosphate (ALP) showed damage to the cell membrane in the presence of complex 3 without irradiation. The GePcSmix complex caused a relatively large increase in inflammation and a high intracellular ATP.
- Full Text:
- Authors: Seotsanyana-Mokhosi, Itumeleng , Kresfelder, Tina , Abrahamse, Heidi , Nyokong, Tebello
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/286115 , vital:56241 , xlink:href="https://doi.org/10.1016/j.jphotobiol.2005.12.004"
- Description: The photodynamic activity of water soluble mixed sulfonated metallophthalocyanines complexes: GePcSmix, SnPcSmix and SiPcSmix on human oesophageal carcinoma (SNO) cells are reported, and compared with the activity of the unmetallated H2PcSmix and of the newly synthesized water soluble adjacently substituted binaphthalo phthalocyanine (complex 3). The alkaline phosphate (ALP) showed damage to the cell membrane in the presence of complex 3 without irradiation. The GePcSmix complex caused a relatively large increase in inflammation and a high intracellular ATP.
- Full Text:
The identification of mammalian species through the classification of hair patterns using image pattern recognition
- Moyo, Thamasanqa, Bangay, Shaun D, Foster, Greg
- Authors: Moyo, Thamasanqa , Bangay, Shaun D , Foster, Greg
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/432938 , vital:72914 , https://doi.org/10.1145/1108590.1108619
- Description: The identification of mammals through the use of their hair is important in the fields of forensics and ecology. The application of computer pattern recognition techniques to this process provides a means of reducing the subjectivity found in the process, as manual techniques rely on the interpretation of a human expert rather than quantitative measures. The first application of image pattern recognition techniques to the classification of African mammalian species using hair patterns is presented. This application uses a 2D Gabor filter-bank and motivates the use of moments to classify hair scale patterns. Application of a 2D Gabor filter-bank to hair scale processing provides results of 52% accuracy when using a filter-bank of size four and 72% accuracy when using a filter-bank of size eight. These initial results indicate that 2D Gabor filters produce information that may be successfully used to classify hair according to images of its patterns.
- Full Text:
- Authors: Moyo, Thamasanqa , Bangay, Shaun D , Foster, Greg
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/432938 , vital:72914 , https://doi.org/10.1145/1108590.1108619
- Description: The identification of mammals through the use of their hair is important in the fields of forensics and ecology. The application of computer pattern recognition techniques to this process provides a means of reducing the subjectivity found in the process, as manual techniques rely on the interpretation of a human expert rather than quantitative measures. The first application of image pattern recognition techniques to the classification of African mammalian species using hair patterns is presented. This application uses a 2D Gabor filter-bank and motivates the use of moments to classify hair scale patterns. Application of a 2D Gabor filter-bank to hair scale processing provides results of 52% accuracy when using a filter-bank of size four and 72% accuracy when using a filter-bank of size eight. These initial results indicate that 2D Gabor filters produce information that may be successfully used to classify hair according to images of its patterns.
- Full Text:
The inducement of a contract by duress of goods - a reappraisal
- Authors: Glover, Graham B
- Date: 2006
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/70734 , vital:29722 , https://hdl.handle.net/10520/EJC54192
- Full Text: false
- Authors: Glover, Graham B
- Date: 2006
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/70734 , vital:29722 , https://hdl.handle.net/10520/EJC54192
- Full Text: false
The Need for Centralised, Cross Platform Information Aggregation
- Otten, Fred, Irwin, Barry V W, Slay, Hannah
- Authors: Otten, Fred , Irwin, Barry V W , Slay, Hannah
- Date: 2006
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/428773 , vital:72535 , https://d1wqtxts1xzle7.cloudfront.net/2355475/8jlt6v8tz4wmhs6.pdf?1425084143=response-content-disposi-tion=inline%3B+filename%3DThe_need_for_centralised_cross_platform.pdfExpires=1714743760Signature=fsImuFaOfYc2FtUC88DqRrK1Anh84~rvBsZt2j46BfPyKMbbmswGZN5E2ajRJ7tZi5SZ4zQJvI5U6L47nmoXlNA0~Vo3pON-sYEo6Kn3TiTLvxwUpPQALnP7IvL-EEhgh11T-OuNZf0Q8QArxk6iqi4zjiOYbHUb~FDWw8MJ7ekH~frNS75mDrjpZ4xL8MqPNRHctaR3E5m~4i71SYO8hfbZw4vu7AhNNNvrRoIhbtLCEUsg-j7TkBDgVHts8LCsM5knmEKwgQTSBQTkLoRuNmXngqYikjvL7jUuHXibjSVaMSD78WRqXE~LDDkT7KXU7EbkPXzjRYJyamQ5qDXa3A__ey-Pair-Id=APKAJLOHF5GGSLRBV4ZA
- Description: With the move towards global and multi-national companies, information technology infrastructure requirements are increasing. As the size of these computer networks increases, it becomes more and more difficult to moni-tor, control, and secure them. Network security involves the creation of large amounts of information in the form of logs and messages from a number of diverse devices, sensors, and gateways which are often spread over large geographical areas. This makes the monitoring and control difficult, and hence poses security problems. The aggregation of information is necessary in information audits, intrusion detection, network monitoring and management. The use of different platforms and devices complicates the problem, and makes aggregation more difficult. Network security administrators and security researchers require aggregation to simplify the analysis and comprehension of activity across the entire net-work. Centralised information aggregation will help deal with redundancy, analysis, monitoring and control. This aids the detection of wide spread attacks on global organisational networks, improving intrusion detection and mitigation. This paper discusses and motivates the need for central-ised, cross platform information aggregation in greater detail. It also sug-gests methods which may be used, discusses the security issues, and gives the advantages and disadvantages of aggregation.
- Full Text:
- Authors: Otten, Fred , Irwin, Barry V W , Slay, Hannah
- Date: 2006
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/428773 , vital:72535 , https://d1wqtxts1xzle7.cloudfront.net/2355475/8jlt6v8tz4wmhs6.pdf?1425084143=response-content-disposi-tion=inline%3B+filename%3DThe_need_for_centralised_cross_platform.pdfExpires=1714743760Signature=fsImuFaOfYc2FtUC88DqRrK1Anh84~rvBsZt2j46BfPyKMbbmswGZN5E2ajRJ7tZi5SZ4zQJvI5U6L47nmoXlNA0~Vo3pON-sYEo6Kn3TiTLvxwUpPQALnP7IvL-EEhgh11T-OuNZf0Q8QArxk6iqi4zjiOYbHUb~FDWw8MJ7ekH~frNS75mDrjpZ4xL8MqPNRHctaR3E5m~4i71SYO8hfbZw4vu7AhNNNvrRoIhbtLCEUsg-j7TkBDgVHts8LCsM5knmEKwgQTSBQTkLoRuNmXngqYikjvL7jUuHXibjSVaMSD78WRqXE~LDDkT7KXU7EbkPXzjRYJyamQ5qDXa3A__ey-Pair-Id=APKAJLOHF5GGSLRBV4ZA
- Description: With the move towards global and multi-national companies, information technology infrastructure requirements are increasing. As the size of these computer networks increases, it becomes more and more difficult to moni-tor, control, and secure them. Network security involves the creation of large amounts of information in the form of logs and messages from a number of diverse devices, sensors, and gateways which are often spread over large geographical areas. This makes the monitoring and control difficult, and hence poses security problems. The aggregation of information is necessary in information audits, intrusion detection, network monitoring and management. The use of different platforms and devices complicates the problem, and makes aggregation more difficult. Network security administrators and security researchers require aggregation to simplify the analysis and comprehension of activity across the entire net-work. Centralised information aggregation will help deal with redundancy, analysis, monitoring and control. This aids the detection of wide spread attacks on global organisational networks, improving intrusion detection and mitigation. This paper discusses and motivates the need for central-ised, cross platform information aggregation in greater detail. It also sug-gests methods which may be used, discusses the security issues, and gives the advantages and disadvantages of aggregation.
- Full Text:
The Representation of, and Control over Mixing Desks via a Software-Based Matrix
- Foss, Richard, Foulkes, Phillip
- Authors: Foss, Richard , Foulkes, Phillip
- Date: 2006
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/427306 , vital:72429 , https://www.aes.org/e-lib/browse.cfm?elib=13701
- Description: The control over all the parameters of a mixing desk can be a daunting task. This paper describes a software system that has been created to represent the signal processing and routing functions of MIDI-controllable mixing desks in a conceptually clear manner. Input to output routings are displayed in the form of a matrix, while signal processing functionality can be accessed at the inputs, outputs, and cross-points. XML is used to capture the elements of the mixing desk, and to associate appropriate MIDI control messages with these elements. This enables the same matrix template to be used for many mixing desks. Remote control is enabled by IP-based MIDI routing software known as MIDINet.
- Full Text:
- Authors: Foss, Richard , Foulkes, Phillip
- Date: 2006
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/427306 , vital:72429 , https://www.aes.org/e-lib/browse.cfm?elib=13701
- Description: The control over all the parameters of a mixing desk can be a daunting task. This paper describes a software system that has been created to represent the signal processing and routing functions of MIDI-controllable mixing desks in a conceptually clear manner. Input to output routings are displayed in the form of a matrix, while signal processing functionality can be accessed at the inputs, outputs, and cross-points. XML is used to capture the elements of the mixing desk, and to associate appropriate MIDI control messages with these elements. This enables the same matrix template to be used for many mixing desks. Remote control is enabled by IP-based MIDI routing software known as MIDINet.
- Full Text:
The sharing of pension benefits on divorce: An inevitable affair?
- Authors: Glover, Graham B
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/186723 , vital:44528 , xlink:href="Print only"
- Description: One of the invariable consequences of divorce is that the patrimonial assets of the marriage have to be divided up between the two parties. At a primary level, the way in which this will occur will be determined by a number of factors: the matrimonial property regime under which the parties had been married; the relevant provisions of the Divorce Act (Act 70 of 1979) that deal with the question of the patrimonial consequences of divorce; as well as any agreement on this often ticklish matter that can be reached by the parties prior to the divorce action. Approximately fourteen years ago, section 7 of the Divorce Act was amended to allow a divorced spouse to share in the pension interests of the other spouse. There is some polemic, though, as to the interpretation of this provision: in particular, it is not clear whether this pension benefit will automatically form part of the assets that are susceptible to division, or whether a prayer to this effect must specifically be sought. After a consideration of the current legal position regarding the sharing of pension benefits generally, this note will examine this specific debate.
- Full Text:
- Authors: Glover, Graham B
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/186723 , vital:44528 , xlink:href="Print only"
- Description: One of the invariable consequences of divorce is that the patrimonial assets of the marriage have to be divided up between the two parties. At a primary level, the way in which this will occur will be determined by a number of factors: the matrimonial property regime under which the parties had been married; the relevant provisions of the Divorce Act (Act 70 of 1979) that deal with the question of the patrimonial consequences of divorce; as well as any agreement on this often ticklish matter that can be reached by the parties prior to the divorce action. Approximately fourteen years ago, section 7 of the Divorce Act was amended to allow a divorced spouse to share in the pension interests of the other spouse. There is some polemic, though, as to the interpretation of this provision: in particular, it is not clear whether this pension benefit will automatically form part of the assets that are susceptible to division, or whether a prayer to this effect must specifically be sought. After a consideration of the current legal position regarding the sharing of pension benefits generally, this note will examine this specific debate.
- Full Text:
The test for duress in the South African law of contract
- Authors: Glover, Graham B
- Date: 2006
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/70756 , vital:29726 , https://hdl.handle.net/10520/EJC53682
- Description: Although it is well-known that a contract induced by duress is voidable at the instance of an aggrieved party, little analysis of this cause of action has been undertaken in South Africa. The test for duress developed by Wessels, and adopted by the courts in Broodryk v Smuts NO 1942 TPD 47, has exercised a vice-grip over this area of contract law. In this article, all five elements of the traditional South African test are subjected to critical examination, and their deficiencies are exposed and discussed. It is argued that the test is neither logically nor conceptually satisfactory, and has hampered development of this area of law. Trends in other jurisdictions, belonging to both the civil-law and the common-law families, are analysed and compared to South African law. On this basis a more modern and coherent test is proposed. This test would be two-pronged, and involve an assessment, in turn, of the lawfulness of the threat made and of whether the party who in fact succumbed to an unlawful threat and entered into the contract was legally justified in doing so.
- Full Text:
- Authors: Glover, Graham B
- Date: 2006
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/70756 , vital:29726 , https://hdl.handle.net/10520/EJC53682
- Description: Although it is well-known that a contract induced by duress is voidable at the instance of an aggrieved party, little analysis of this cause of action has been undertaken in South Africa. The test for duress developed by Wessels, and adopted by the courts in Broodryk v Smuts NO 1942 TPD 47, has exercised a vice-grip over this area of contract law. In this article, all five elements of the traditional South African test are subjected to critical examination, and their deficiencies are exposed and discussed. It is argued that the test is neither logically nor conceptually satisfactory, and has hampered development of this area of law. Trends in other jurisdictions, belonging to both the civil-law and the common-law families, are analysed and compared to South African law. On this basis a more modern and coherent test is proposed. This test would be two-pronged, and involve an assessment, in turn, of the lawfulness of the threat made and of whether the party who in fact succumbed to an unlawful threat and entered into the contract was legally justified in doing so.
- Full Text:
Thinking about fear and freedom:
- Authors: Garman, Anthea
- Date: 2006
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/158794 , vital:40229 , https://hdl.handle.net/10520/EJC146175
- Description: Some convictions have chrystalised for me in the process of putting together this new edition of Rhodes Journalism Review.
- Full Text:
- Authors: Garman, Anthea
- Date: 2006
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/158794 , vital:40229 , https://hdl.handle.net/10520/EJC146175
- Description: Some convictions have chrystalised for me in the process of putting together this new edition of Rhodes Journalism Review.
- Full Text:
Toward visualised network intrusion detection
- van Riel, J.P, Irwin, Barry V W
- Authors: van Riel, J.P , Irwin, Barry V W
- Date: 2006
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/428238 , vital:72496 , https://www.cs.ru.ac.za/research/g02v2468/publications/vanRiel-SATNAC2006.pdf
- Description: To deal with the large volume of network data, contemporary solutions seek to automate the process of detecting intrusive activity. However, intrusion detection systems can produce an overwhelming number of alerts, and many false alarms can obscure serious intrusion attempts. To overcome these difficulties, this paper suggests combining dedicat-ed sensor network monitoring with visualisation. With the aim of evaluat-ing intrusion detection systems, we introduce the idea of using graph-ical representations to superimpose alert information over raw network traffic.
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- Authors: van Riel, J.P , Irwin, Barry V W
- Date: 2006
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/428238 , vital:72496 , https://www.cs.ru.ac.za/research/g02v2468/publications/vanRiel-SATNAC2006.pdf
- Description: To deal with the large volume of network data, contemporary solutions seek to automate the process of detecting intrusive activity. However, intrusion detection systems can produce an overwhelming number of alerts, and many false alarms can obscure serious intrusion attempts. To overcome these difficulties, this paper suggests combining dedicat-ed sensor network monitoring with visualisation. With the aim of evaluat-ing intrusion detection systems, we introduce the idea of using graph-ical representations to superimpose alert information over raw network traffic.
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Towards Central Vulnerability Management By Mobile Phone Operators
- Moyo, Thamsanqa, Irwin, Barry V W, Wright, Madeleineh
- Authors: Moyo, Thamsanqa , Irwin, Barry V W , Wright, Madeleineh
- Date: 2006
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/428787 , vital:72536 , https://www.researchgate.net/profile/Barry-Ir-win/publication/237107512_Securing_mobile_commerce_interactions_through_secure_mobile_web_services/links/5b9a5898a6fdccd3cb4ff6cf/Securing-mobile-commerce-interactions-through-secure-mobile-web-services.pdf
- Description: The application of XML-based approaches in passing vulnerability in-formation between vulnerability management devices or software resid-ing on wired networks has been demonstrated. We propose a proof of concept framework for mobile operators that extends this use of XML into the area of vulnerability management on public land mobile net-works. Our proposed framework allows for a pro-active central man-agement of vulnerabilities found on mobile stations such as mobile phones. Despite the relatively limited number of reported vulnerabilities on mobile stations, such a pre-emptive approach from mobile operators is necessary to acquire the confidence of early adopters in Mobile Commerce. Given the diverse collection of devices and software that exist on a public land mobile network, XML-based approaches are best able to providing the inter-operability required for vulnerability manage-ment on such a network. Our proposed framework leverages web ser-vices by using the Open Vulnerability Assessment Language (OVAL) to provide vulnerability descriptions, and by securing these descriptions in SOAP messages conforming to the OASIS Web Services Security (WSS) standard. We contribute in three areas: firstly, through this framework we show that mobile operators can carry out centralized vul-nerability management on their public land mobile networks comprising of a wide variety of devices and software. Secondly, the assurance of integrity, confidentiality and non-repudiation inherently lacking in OVAL vulnerability descriptions is achieved through their encapsulation in SOAP messages conforming to the OASIS WSS standard. Thirdly, SOAP-based web service implementations allow for integration with vulnerability management tools and devices that do not conform to OVAL.
- Full Text:
- Authors: Moyo, Thamsanqa , Irwin, Barry V W , Wright, Madeleineh
- Date: 2006
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/428787 , vital:72536 , https://www.researchgate.net/profile/Barry-Ir-win/publication/237107512_Securing_mobile_commerce_interactions_through_secure_mobile_web_services/links/5b9a5898a6fdccd3cb4ff6cf/Securing-mobile-commerce-interactions-through-secure-mobile-web-services.pdf
- Description: The application of XML-based approaches in passing vulnerability in-formation between vulnerability management devices or software resid-ing on wired networks has been demonstrated. We propose a proof of concept framework for mobile operators that extends this use of XML into the area of vulnerability management on public land mobile net-works. Our proposed framework allows for a pro-active central man-agement of vulnerabilities found on mobile stations such as mobile phones. Despite the relatively limited number of reported vulnerabilities on mobile stations, such a pre-emptive approach from mobile operators is necessary to acquire the confidence of early adopters in Mobile Commerce. Given the diverse collection of devices and software that exist on a public land mobile network, XML-based approaches are best able to providing the inter-operability required for vulnerability manage-ment on such a network. Our proposed framework leverages web ser-vices by using the Open Vulnerability Assessment Language (OVAL) to provide vulnerability descriptions, and by securing these descriptions in SOAP messages conforming to the OASIS Web Services Security (WSS) standard. We contribute in three areas: firstly, through this framework we show that mobile operators can carry out centralized vul-nerability management on their public land mobile networks comprising of a wide variety of devices and software. Secondly, the assurance of integrity, confidentiality and non-repudiation inherently lacking in OVAL vulnerability descriptions is achieved through their encapsulation in SOAP messages conforming to the OASIS WSS standard. Thirdly, SOAP-based web service implementations allow for integration with vulnerability management tools and devices that do not conform to OVAL.
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Trade and the environmental Kuznets curve: is Southern Africa a pollution haven?
- Nahman, Anton, Antrobus, Geoffrey G
- Authors: Nahman, Anton , Antrobus, Geoffrey G
- Date: 2006
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/143202 , vital:38210 , DOI: 10.1111/j.1813-6982.2005.00055.x
- Description: Evidence that the environmental Kuznets curve (EKC) may be explained by trade patterns casts doubt on the oft‐stated conclusion that economic growth automatically leads to environmental improvement. Trends in net exports as a proportion of consumption for both USA and UK trade with SACU were examined for various dirty industries. Some evidence of pollution haven effects is found, although a similar trend for clean industries suggests that this effect is weak. However, even a general shift in manufacturing industries from North to South (as opposed to a shift in specifically dirty industries) may explain the EKC to some extent.
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- Authors: Nahman, Anton , Antrobus, Geoffrey G
- Date: 2006
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/143202 , vital:38210 , DOI: 10.1111/j.1813-6982.2005.00055.x
- Description: Evidence that the environmental Kuznets curve (EKC) may be explained by trade patterns casts doubt on the oft‐stated conclusion that economic growth automatically leads to environmental improvement. Trends in net exports as a proportion of consumption for both USA and UK trade with SACU were examined for various dirty industries. Some evidence of pollution haven effects is found, although a similar trend for clean industries suggests that this effect is weak. However, even a general shift in manufacturing industries from North to South (as opposed to a shift in specifically dirty industries) may explain the EKC to some extent.
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Trade in reed-based craft products in rural villages in the Eastern Cape, South Africa
- Pereira, Taryn, Shackleton, Charlie M, Shackleton, Sheona E
- Authors: Pereira, Taryn , Shackleton, Charlie M , Shackleton, Sheona E
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/181290 , vital:43716 , xlink:href="https://doi.org/10.1080/03768350600927235"
- Description: Selling traditional craft products made from fibrous plants is an important source of income for economically vulnerable rural women. In the Eastern Cape Province of South Africa, Cyperus textilis and Juncus kraussii have been used for centuries to make products of functional and cultural importance, such as sleeping mats and baskets. In the former Transkei village clusters of Mpozolo and Ntubeni, female crafters harvest the raw material and make and sell the products in their communities and in nearby towns. Interviews with 40 of them revealed what the trade contributes to their livelihoods and what enhances or limits their success. The findings show that crafting contributes vital income to vulnerable households, on average 26 ± 4 per cent of annual household cash income, over 40 per cent for the poorest households and 5–15 per cent for wealthier households. Lack of access to non-traditional markets was identified as the main constraint on the trade.
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- Authors: Pereira, Taryn , Shackleton, Charlie M , Shackleton, Sheona E
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/181290 , vital:43716 , xlink:href="https://doi.org/10.1080/03768350600927235"
- Description: Selling traditional craft products made from fibrous plants is an important source of income for economically vulnerable rural women. In the Eastern Cape Province of South Africa, Cyperus textilis and Juncus kraussii have been used for centuries to make products of functional and cultural importance, such as sleeping mats and baskets. In the former Transkei village clusters of Mpozolo and Ntubeni, female crafters harvest the raw material and make and sell the products in their communities and in nearby towns. Interviews with 40 of them revealed what the trade contributes to their livelihoods and what enhances or limits their success. The findings show that crafting contributes vital income to vulnerable households, on average 26 ± 4 per cent of annual household cash income, over 40 per cent for the poorest households and 5–15 per cent for wealthier households. Lack of access to non-traditional markets was identified as the main constraint on the trade.
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Unique electrochemical behavior of tantalum (V) phthalocyanine
- Tau, Prudence, Nyokong, Tebello
- Authors: Tau, Prudence , Nyokong, Tebello
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/286139 , vital:56243 , xlink:href="https://doi.org/10.1142/S1088424606000090"
- Description: The electrochemical and spectroscopic behavior of tantalum(V) phthalocyanine are presented. The NMR spectra is consistent with the lack of symmetry of the complex. Cyclic (CV) and square wave (SWV) voltammetries, and spectroelectrochemistry, were employed in the study of the complex. Two one-electron reductions and a simultaneous 4-electron reduction were observed. Reduction occurs first at the metal to form a Ta(IV) species, followed by ring based processes.
- Full Text:
- Authors: Tau, Prudence , Nyokong, Tebello
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/286139 , vital:56243 , xlink:href="https://doi.org/10.1142/S1088424606000090"
- Description: The electrochemical and spectroscopic behavior of tantalum(V) phthalocyanine are presented. The NMR spectra is consistent with the lack of symmetry of the complex. Cyclic (CV) and square wave (SWV) voltammetries, and spectroelectrochemistry, were employed in the study of the complex. Two one-electron reductions and a simultaneous 4-electron reduction were observed. Reduction occurs first at the metal to form a Ta(IV) species, followed by ring based processes.
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Urban forestry–A cinderella science in South Africa?
- Authors: Shackleton, Charlie M
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/183092 , vital:43911 , xlink:href="https://doi.org/10.2989/10295920609505255"
- Description: The benefits of forests (in their broadest sense) and of trees to the natural environment and rural communities are well known throughout the world, including in South Africa (e.g. see chapters in Lawes et al. 2004). The presence of these benefits has also been extrapolated to urban situations, where natural forests and veld might be left in situ, or trees planted in public spaces, or in private gardens. These benefits span the social, aesthetic, health, environmental and economic spheres.
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- Authors: Shackleton, Charlie M
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/183092 , vital:43911 , xlink:href="https://doi.org/10.2989/10295920609505255"
- Description: The benefits of forests (in their broadest sense) and of trees to the natural environment and rural communities are well known throughout the world, including in South Africa (e.g. see chapters in Lawes et al. 2004). The presence of these benefits has also been extrapolated to urban situations, where natural forests and veld might be left in situ, or trees planted in public spaces, or in private gardens. These benefits span the social, aesthetic, health, environmental and economic spheres.
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Urban fuelwood demand and markets in a small town in South Africa: Livelihood vulnerability and alien plant control
- Shackleton, Charlie M, McConnachie, Matthew M, Chauke, Maphambe I, Mentz, J, Sutherland, F, Gambiza, James, Jones, R
- Authors: Shackleton, Charlie M , McConnachie, Matthew M , Chauke, Maphambe I , Mentz, J , Sutherland, F , Gambiza, James , Jones, R
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/181224 , vital:43710 , xlink:href="https://doi.org/10.1080/13504500609469697"
- Description: Fuelwood is the primary energy for most households throughout the developing world. With increasing urbanization and declining local availability of fuelwood, a growing proportion of households obtain their fuelwood by purchasing it. These fuelwood markets are the key nexus in supply and demand scenarios and can be potentially significant points for intervention to address energy security amongst the urban poor. This paper reports on the fuelwood demand and marketing in a small town in South Africa. Despite the availability of more modern fuels and state subsidization of electricity, fuelwood was still used by half the households. Annual demand was 1.2 t per household. Over half of the households bought their fuelwood requirements because local stocks were limited. Those households that did collect their own fuelwood were significantly poorer than households that purchased fuelwood, as well as households that did not use fuelwood at all. Fuelwood markets operated through 45-60 vendors who transported fuelwood from further afield. Income from the fuelwood trade was low, but was strongly linked to hours worked. Thus, vendors working a full week did earn a meaningful income, especially in the context of high unemployment in the area. Fuelwood vendors also provided casual employment opportunities for unskilled labour. Most vendors harvested fuelwood from commonage lands, with most of the wood being from alien species. Local stocks of wood are declining in the face of constant transformation of commonage to residential areas, and a national water and biodiversity conservation programme to eradicate alien plants. This decline poses a threat to the financial viability of fuelwood markets. Yet, an opportunity exists to incorporate the vendors into the alien plant clearing programme, since they already perform such a function.
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- Authors: Shackleton, Charlie M , McConnachie, Matthew M , Chauke, Maphambe I , Mentz, J , Sutherland, F , Gambiza, James , Jones, R
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/181224 , vital:43710 , xlink:href="https://doi.org/10.1080/13504500609469697"
- Description: Fuelwood is the primary energy for most households throughout the developing world. With increasing urbanization and declining local availability of fuelwood, a growing proportion of households obtain their fuelwood by purchasing it. These fuelwood markets are the key nexus in supply and demand scenarios and can be potentially significant points for intervention to address energy security amongst the urban poor. This paper reports on the fuelwood demand and marketing in a small town in South Africa. Despite the availability of more modern fuels and state subsidization of electricity, fuelwood was still used by half the households. Annual demand was 1.2 t per household. Over half of the households bought their fuelwood requirements because local stocks were limited. Those households that did collect their own fuelwood were significantly poorer than households that purchased fuelwood, as well as households that did not use fuelwood at all. Fuelwood markets operated through 45-60 vendors who transported fuelwood from further afield. Income from the fuelwood trade was low, but was strongly linked to hours worked. Thus, vendors working a full week did earn a meaningful income, especially in the context of high unemployment in the area. Fuelwood vendors also provided casual employment opportunities for unskilled labour. Most vendors harvested fuelwood from commonage lands, with most of the wood being from alien species. Local stocks of wood are declining in the face of constant transformation of commonage to residential areas, and a national water and biodiversity conservation programme to eradicate alien plants. This decline poses a threat to the financial viability of fuelwood markets. Yet, an opportunity exists to incorporate the vendors into the alien plant clearing programme, since they already perform such a function.
- Full Text: